Kinetics and thermodynamics of isothermal curing reaction of epoxy-4, 4′-diaminoazobenzene reinforced with nanosilica and nanoclay particles

✍ Scribed by M. Barghamadi

• Publisher: Society for Plastic Engineers
• Year: 2009
• Tongue: English
• Weight: 403 KB
• Volume: 31
• Category: Article
• ISSN: 0272-8397
• DOI: 10.1002/pc.20930

✦ Synopsis

Abstract

The kinetics of the cure reaction for a system of bisphenol‐A epoxy resin (DGEBA), with 4, 4′‐diaminoazobenzene (DAAB), reinforced with nanosilica (NS), and nanoclay (NC) by means of isothermal technique of differential scanning calorimetry were studied. The Kamal autocatalytic‐like kinetic model was used to estimate the reaction orders (m, n), rate constants (k~1~, k~2~), and also active energies (E~a~) and pre‐exponential factors (A) of the curing reaction. However, the existence of NS and NC with hydroxyl groups in the structure improves the cure reaction and influence the rate of reaction and therefore kinetics parameters. The E~a~ of cure reaction of DGEBA/DAAB system showed a decrease when nanoparticles were present and therefore the rate of the reaction was increased. Using the rate constants from the kinetic analysis and transition state theory, thermodynamic parameters such as enthalpy (Δ__H__^#^), entropy (Δ__S__^#^), and Gibbs free energy (Δ__G__^#^) changes were also calculated. The thermodynamic functions were shown to be very sensitive parameters for evaluation of the cure reaction. POLYM. COMPOS., 31:1442–1448, 2010. © 2009 Society of Plastics Engineers